Sewing-machine feed



June 21, 1949. s. ADLER SEWING MACHINE FEED 2 Sheets-Sheet 1 Filed Aug. 30, 1946 I NVE .V'I'OR. 5010mm fldlzr M M and llllllllh ln! June 21, 1949. ADLER 2,473,934

SEWING MACHINE FEED Filed Aug. 30, 1946 2 Sheets-Sheet 2 g 5 20 g 11 l g i 6 12 INVENTOR.

J'a/dman 17d! ATTORNEYS Patented June 21, 1949 UNITED STATES PATENT OFFICE Claims.

This invention relates to a feed mechanism for sewing machines.

Sewing machines have already been built which permit to reverse the direction in which the material is fed through the machine as well as to render the feed temporarily inoperative. It is an object of this invention to improve such reversing mechanisms and to provide a simplified and, nevertheless, sturdier and more economical structure. A further object is to provide a reversing device for the feed which does not take up much space and, therefore, lends itself for use in a machine of small overall dimensions, as, for instance, a portable machine.

The invention, broadly, is carried out by combining with the conventional eccentric drive for the feed dog a train of gears which includes a plurality of intermediate gears so disposed on a swivel member that the gears can selectively be brought into and out of engagement by varying the position of the swivel member.

My invention will be explained with reference to the following drawings, of which Fig. 1 is a horizontal section through the base portion of a sewing machine incorporating the new type of gearing;

Fig. 2 is a vertical section on lines 22 of Fig. 1;

Fig. 3 is a similar section on lines 33 of Fig. 1 and Figs. 4a, 4b and 4c illustrate diagrammatically three alternative positions of the intermediate gears.

Referring to the drawings and, in the first place particularly, to Fig. 1, it will be seen that the machine is provided with a main drive shaft I which receives motive power from a motor M through a transverse shaft 2. The shaft 1 constitutes the driving means for the feed dog 2a and the bobbin assembly 3 for the lower thread. The embodiment shows the shaft as comprisin the referred to main shaft I and a short stub shaft 4 which is connected to the main shaft by a coupling 5. This coupling and its associated linkage 5a does not form any part of this invention and is not claimed herein. Its mechanism, therefore, will not be described to any greater detail in this specification and the terms drive shaft or motion transmitting shaft throughout the specification and claims are to be understood as including the composite unit of the main shaft l and its short front end 4.

The feed dog 2a. is of the conventional type wherein the feeding movement is accomplished by the reciprocating motion of a toothed member. This latter member is supported by a carrier 6 which, as appears best from Fig. 3, is adapted by means of a spindle l and slot 8 to pass through a forward and backward movement transversely of the machine. Its front end is forked so as to provide two prongs 5i and iii of unequal length and a curved edge portion H disposed between the prongs. The rear face of the carrier is fiat and adapted to be abutted by an end plate l2, disposed on the shank it of a piston IS. The piston is slideably carried in a tube I4 which projects from the rear face of the machine and, which at its front end, has an apertured end bushing 15. A spring I! tends to force the piston outward and to press the abutment plate against the rear end of the feed do carrier.

A shaft 18, disposed at right angles with the longitudinal face of the carrier 5, supports an eccentric disc N) which, upon rotation of the shaft, describes an oscillating movement along the contact face if. A disc 25 is rigidly secured to a rotatable shaft 2! and the shaft also carries an arcuate cam member 22. The cam member has a curvilinear face and abuts the front end of the longer prong 9 of the carrier. The disc has a calibration which, through an aperture of the frame,

is visible from the outside. By changing the position of a lever 23, the disc may be rotated, and the point of contact between the cam and the prong 9 may thus be varied.

It will be understood that lifting of the lever extends the abutment face of the cam towards prong 9 and thereby shortens the stroke of the carrier, and vice versa. In this manner, an adjustment of the stitch length is obtained. It will also be understood that the reciprocating action of the carrier is accomplished by the interaction of the eccentric l 9 and the spring piston Hi.

The gear mechanism proper is best illustrated in Fig. 2. It comprises a main gear 24 disposed on the drive shaft l, 4 and another main gear 25, which latter gear, is carried by the shaft l8 of the eccentric. Intermediate these main gears are two idler gears 25 and 2? which may have slightly different diameters. The intermediate gears are carried by a, swivel member which is fulcrumed on and free to rotate about shaft iii of the eccentric and which, in the embodiment shown, consists of a plate 28 of roughly parallelogram form and an arm 29 extending from one of its corner portions. The arm is connected by linkage 30, 3| to a square shaped actuating shaft formed of two telescoped members 32 and 32a to permit its lengthwise expansion, the two shaft members being secured against relative rotation by a slot and spline arrangement.

By turning the lever 33, a fraction of a turn is imparted to the actuating shaft and an oscillating movement is transmitted to the carrier plate through the forementioned links and the arm 29. The oscillating movement results in a forward or backward inclination of the face 29a of the carrier. Therefore, either the upper intermediate gear 26 or the lower intermediate gear 21 is brought into mesh with the main gear 24. These two positions are illustrated in Figs. 4b and 40. In addition, there is an intermediate position, shown in Fig. 2 and, diagrammatically, in Fig. 4a, where neither idler gear is in engagement with the main drive gear. The device, as illustrated, also shows the lower intermediate gear as engaging the gear of the drive shaft in all three positions of the swivel member and, likewise, the two intermediate gears as relatively in mesh at all times.

The mechanism operates as follows:

When the lever 33 of the actuating shaft is moved to its medial position, both intermediate ears will be out of engagement with the gear of the drive shaft, as shown in Fig. 4a. In this position, no motion is transmitted to the eccentric and the feed is, therefore, rendered inoperative permitting adjustment of the material and operations like darning where no continuous mechanical feed is desired. When the lever is moved to its two end positions, the intermediate gears will be disposed as shown in Figs. 4b and 40. In the position according to the first mentioned figure, intermediate gear 26 is engaged by main drive gear 24 and intermediate gear 21 is in engagement with gear 25 of the eccentric. Since both intermediate gears are also in relative engagement motion is transmitted from the main drive gear to intermediate gear 26, thence to the other intermediate gear and finally to the ear of the eccentric. Since there are two idler gears interposed in this position between the main gears a reversal of motion takes place.

By moving the lever to its other end position (Fig. 4c) the swivel member is again shifted, this time projecting the lower right hand corner and, therefore, bringing lower intermediate gear 27 into mesh with main gear 24, while gear 21, at the same time, is also in engagement with gear 25 of the eccentric. The other intermediate gear, though rotated by its companion gear, is out of engagement with any of the main gears. Accordingly, transmission of motion takes place from drive gear 24 to intermediate gear 21 and then to the gear of the eccentric. Since in this position only one intermediate gear forms part r of the motion transmitting mechanism, the direction of the motion is maintained.

It should be understood that two intermediate gears have been shown in this description by way of example only. It will be manifest that any number of gears might be used as long as an odd or an even number of such gears can selectively be brought into and out of engagement, in order to change the number of gears included in the motion transmission and, thus, to change the sign of the train value which determines the direction of motion. Further, the position of the idler gears While in neutral (Figs. 2 and 4a) is, of course, a matter of discretion provided that the transmission of motion between the main gears is broken somewhere along the line of ears.

Other modifications are possible without departing from the spirit of the invention and I, therefore, do not wish to be limited otherwise than by the following claims.

What I claim is:

1. In a sewing machine in combination a base provided with a deck, a main drive shaft supported within said base and below said, deck, a gear connected to rotate with said drive shaft, a further shaft, a second gear secured to rotate with said further shaft, 9, shiftable carrier plate fulcrumed on said further shaft, a pair of intermeshing gears supported by said plate and disposedaccording to the position to which said plate is shifted and under continued rotation of the drive shaft gear in one directionto connect the drive shaft gear, through the gears of the carrier plate, to rotate the second gear in clockwise and counter-clockwise directions and to prevent the main drive gear from driving the second gear, a manually shiftable means accessibly disposed with respect to said base and deck and connected to said plate to shift the same, a feed dog slidably mounted for reciprocation with respect to said base and means carried by said further shaft and connected with said dog to cause reciprocation of the same as said further shaft is rotated.

2. In a sewing machine in combination a base provided with a deck, a main drive shaft supported within said base and below said deck, a gear connected to rotate with said drive shaft, a further shaft, a second gear secured to rotate with said further shaft, a shiftable carrier plate fulcrumed on said further shaft, a pair of intermeshing gears supported by said plate and disposedaccording to the position to which said.

plate is shifted and under continued rotation of the drive shaft gear in one directionto connect the drive shaft gear, through the gears of the carrier plate, to rotate the second gear in clockwise and counter-clockwise directions and to prevent the main drive gear from driving the second gear, a manually shiftable means accessibly disposed with respect to said base and deck and connected to said plate to shift the same, a feed dog slidably mounted for reciprocation with respect to said base, means carried by said further shaft and connected with said dog to cause reciprocation of the same as said further shaft is rotated, means for varying the range of reciprocation of said feed dog and a second manually shiftable means accessibly disposed with respect to said base and connected to said varying means for operating the same.

3. In a sewing machine in combination abase provided with a deck, a main drive shaft supported within said base and below said deck, a gear connected to rotate with said drive shaft, a

further shaft, a second gear secured to rotate with said further shaft, a shiftable carrier plate fulcrumed on said further shaft, a pair of intermeshing gears supported by said plate and disposedaccording to the position to which said plate is shifted and under continued rotation of vent the main drive gear from driving the second gear, a manually shiftable means accessibly disposed with respect to said base and deck and connected to said plate to shift the same, a feed dog, a carrier supporting said dog, means for slidably supporting said carrier, a spring acting against one end of said carrier to urge the same in one direction, prongs forming parts of said carrier and connected by a curved edge portion and a circular cam carried by said further shaft and disposed between said prongs in engagement with said curved edge portion to shift said carrier and dog to compress said spring.

4. In a sewing machine in combination a base provided with a deck, a main drive shaft supported Within said base and below said deck, a gear connected to rotate with said drive shaft, a further shaft, a second gear secured to rotate with said further shaft, a shiftable carrier plate fulcrumed on said further shaft, a pair of intermeshing gears supported by said plate and disposed according to the position to which said plate is shifted and under continued rotation of the drive shaft gear in one direction-to connect the drive shaft gear, through the gears of the carrier plate, to rotate the second gear in clockwise and counterclockwise directions and to prevent the main drive gear from driving the second gear, a manually shiftable means accessibly disposed with respect to said base and deck and connected to said plate to shift the same, a feed dog, a carrier supporting said dog, means for slidably supporting said carrier, a spring acting against one end of said carrier to urge the same in one direction, prongs forming parts of said carrier and connected by a curved edge portion, a circular cam carried by said further shaft and disposed between said prongs in engagement with said curved edge portion to shift said carrier and dog to compress said spring, one of said prongs extending beyond the end of the other of the same, means engageable with the end of said one prong for varying the range of reciprocation of said carrier and a second manually shiftable means accessibly disposed with respect to said base and connected to said varying means for operating the same.

5. In a sewing machine in combination, a base provided with a deck, a feed dog movable adjacent said deck, a carrier for said dog, means for slidably supporting said carrier for reciprocation, a spring acting against one end of said carrier for urging the same in one direction, a pair of prongs forming a part of said carrier and connected by a curved edge portion, a rotatable shaft, a circular cam mounted by said shaft and disposed between said prongs to engage said curved edge portion, one of said prongs being of greater length than the other, a further cam rotatable with respect to said base and engaging the end of said longer prong and manually shiftable means accessibly disposed with respect to said base and connected to said further cam for turning the same.

SOLOMON ADLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 216,791 Grover June 24, 1879 373,164 Whitney Nov. 15, 1887 575,339 Diehl Jan. 19, 1897 1,305,077 Dunbar May 27, 1919 

